“Fundamentally if you’re looking at World Population Day, it is at heart a women’s rights issue,” said Roger-Mark DeSouza director of population, environmental security, and resilience at the non-partisan policy Wilson Center, based in Washington, D.C.

World Population Day is meant to draw attention to the challenges we face with a human population that is constantly growing. Rapid population growth in the poorest countries leads to rapid consumption of natural resources, which makes it difficult for countries to feed themselves and recover from the effects of climate change, such as increased flooding, DeSouza said.

The population of the least developed countries grows about 2.4% per year, with a birth rate of 4.3 children per woman. DeSouza said this rate of growth will be unsustainable if the level of consumption in developing countries reaches that of the industrialized world.

Many African countries are addressing this issue by investing money in women’s empowerment, including the unmet need for contraceptives and education, he said. Improving women’s rights can be a powerful tool to tackle unsustainable population growth:

Access to safe family planning options not only allows women to become more economically productive but would also result in a 75% decline in unintended pregnancies, unplanned births and induced abortions in developing regions, according to the Guttmacher Institute, a reproductive justice, and sexual health research institution.

Access to contraception and information about family planning are vital components of gender equality. According to the UNFPA, "When women and couples are empowered to plan whether and when to have children, women are better enabled to complete their education; women’s autonomy within their households is increased, and their earning power is improved."